function addhover() {
	var navli,i;
	// loop through all elements in the nav
	navli = document.getElementById('centeredmenu').getElementsByTagName('li')
	for(i=0;i<navli.length;i++) {
		// add the hover functions to the li onmouseover and onmouseout
		navli[i].onmouseover=function(){hover(this,'hover');};
		navli[i].onmouseout=function(){hover(this,'');};
	}
}
function hover(o,sClass) {
	if (o) {
		o.className = sClass;
	}
}
addhover();